This invention relates to a system and structure for the individual housing and raising of underwater animals and mariculture; and more particularly to an expandable vertical housing and feeding structure adapted for the optimum use of underwater cage space, and further providing individual control over the amount of food delivered to each cage. While the structure of the invention herein disclosed has been especially designed for the growing of lobsters, it is adaptable to be used with many forms of underwater animal life, including all species of mariculture. Therefore, the term "animal" or "animals", as used in this application, will refer to most species of mariculture and other underwater life.
The prior art reveals numerous approaches devised for housing and feeding underwater animals. These prior art devices have resulted in large part from the high demand for such animals--whether as food for human consumption or as bait. Because of this high demand, and because underwater animals usually require very little space in which to grow, the raising of such animals lends itselve to a high density type of cage system.
Illustrative of the prior art structures used for raising underwater animals are the following patents: Wishner, U.S. Pat. No. 4,007,709 (1977); Serfling, U.S. Pat. No. 3,916,833 (1975); and Plante, U.S. Pat. No. 3,815,546 (1974). These prior art caged systems are characterized in general by a vertical stacking of individual cages.
All of the prior art underwater caged systems with which the inventors of this application are familiar suffer from one or more of the following problems. First, the caged structures must often support the weight of the cage, the water inside of the cage, and the animal. This often results in a needlessly bulky, strong, and expensive structure. Secondly, the prior art caged systems are not designed to allow a controlled feeding to be easily performed from above the surface of the water to the individual cages below the water. Moreover, even if a controlled, individualized, feeding system is provided, the entrapment of smaller animals and other debris can easily plug up the feeding mechanism.
Thirdly, prior art caged structures are often difficult to inspect for dead animals and for the accumulation of uneaten food and fecal material. Fourthly, the prior art systems provide no easy method for the removal of such undesirable accumulations. Furthermore, if a method is provided to prevent the accumulation of uneaten food and fecal material, then this same method often allows only partially eaten food to fall out of the cage, thereby causing waste.
Fifthly, prior art caged structures are often limited in size, as well as to the number of cages that can be used, thereby limiting the number of animals that can be housed without the procurement of a whole new system. Sixthly, the natural flow of oxygenated water through the system is often restricted, thereby causing the use of a forced oxygenated system which can be expensive both in manufacturing and operating costs.
Lastly, the prior art caged systems require that animals, as they grow, be physically moved from smaller cages to larger cages so as to prevent stunting of their growth.